Jim,
One thing that you might consider is a self directed defined BENEFIT pension plan. It works very much like a self directed IRA at a brokerage firm, but there is far more govt. paperwork, and it is expensive to set up and maintain. (About $2,000 for initial setup, and $1,000 for annual reports.) You would need an actuary who specializes in single person S-Corp. pensions, and a brokerage firm as custodian. I know that Schwab handles them, but that USAA did not as of about seven years ago.
Scott, is your firm set up to handle this type of account?
The advantage is that it allows you to set aside, tax deferred, a much greater amount of money each year, quite possibly double your salary for somebody your age. This also sidesteps most of the social security tax problem. This might actually bring your IRS AGI down low enough to qualify for a Roth IRA in addition to the retirement plan.
The rules on these pension plans are actually quite loose, and a creative accountant will change the assumptions each year to fit the amount of money that you wish to stash in the pension plan that year.
Bryan